PsycCRITIQUES - Contemporary Psychology: APA Review of Books
Hypnosis and Memory—and Much, Much More
A review of
Hypnosis and Memory
Helen M. Pettinati (Ed.)
New York: Guilford Press, 1988. 301 pp. ISBN 0-89862-338-3. $30.00

Reviewed by
John F. Kihlstrom

Hypnosis is a social interaction in which one person responds to suggestions offered by another for various kinds of imaginative experiences. Positive response to hypnotic suggestions sometimes entails profound alterations in mental functioning, particularly in the domain of memory. The most intensely studied of these memory phenomena is hypnotic (or posthypnotic) amnesia—the difficulty that some subjects have in remembering events and experiences that transpired while they were hypnotized. The other side of the coin is hypnotic hypermnesia, where it is suggested that the subject can remember, while hypnotized, things that could not be remembered otherwise. Related to hypermnesia is hypnotic age regression, in which it is suggested that the subject actually grows younger and returns to an earlier period of his or her life. Finally, hypnotized subjects can be given suggestions for paramnesias that result in distorted recollections of events that they have experienced either in or out of hypnosis. Although such suggestions have an undeniable effect on the experience of remembering, the precise nature of their effects is a subject of considerable dispute. Into this situation, characterized by a mix of claim and counterclaim, folklore and scientific evidence, assumption and fact, Helen Pettinati has brought 17 distinguished contributors who have written chapters bearing on almost every aspect of hypnosis, memory, and related topics.

Hilgard and Bowers begin the book with an overview of the general principles of memory function, largely disregarding the effects of hypnosis but with a clear eye toward the specific chapters that follow. They argue that the degree to which a memory accurately corresponds to some past event is conceptually independent of the degree to which a person experiences the recollection as valid and that the actual correlation between them is an empirical matter. The tendency of reconstructive memory to produce cryptomnesias, confabulations, and paramnesias of various sorts may well be exacerbated by the imaginative involvement characteristic of the hypnotic situation.

The first major section of the volume contains four chapters dealing specifically with various aspects of the claim that hypnosis can improve memory. M. Orne and his collaborators (Whitehouse, Dinges, and E. C. Orne) provide a sweeping overview of the effects of hypnosis, guided imagery, leading questions and other postevent information, and emotional and contextual reinstatement on memory—the literature that the courts consider when deciding the admissibility of hypnotically "refreshed" memories. If memory is unreliable, as it sometimes seems to be, hypnosis only appears to make things worse. Although hypnotic hypermnesia may be useful in the clinical consulting room, where fantasies may be as important as facts, hypnosis may well subvert the fact-finding task of the jury and should be prohibited in the forensic situation. Erdelyi takes a more focused look at the hypnotic and nonhypnotic hypermnesia and concludes that hypnosis adds nothing to, and may well detract from, the progressive enhancement of memory that can occur over multiple test trials. Perry and his colleagues (Laurence, D'Eon, and Tallant) take a close look at hypnotic age regression (with a passing glance at pastlives regression and reincarnation therapy): Although the experience of being young again may be subjectively convincing, the objective evidence is that such suggestions produce, at best, a subtle admixture of fact and fantasy. Sheehan summarizes his extensive research program on the vulnerability of hypnotic subjects to the "misinformation" effect. Although it would seem that the responsiveness to suggestion characteristic of hypnotic subjects would make them more prone to leading questions and other interrogative biases, the laboratory evidence is, to this reader at least, a mixed bag: Sometimes it does, sometimes it does not.

Although the section on the hypnotic enhancement of memory has a kind of debunking quality, a second section on memory disruptions has a more positive ring to it. Evans provides an overview of his extensive inquiry into the mechanisms of posthypnotic amnesia, with an emphasis on the loss of contextual information pertaining to the forgotten events. Moving somewhat further afield, Bennett blends anecdotes, clinical case series, and formal experiments to support the hypothesis that memories of surgical events may be encoded and influence postoperative behavior, even under adequate doses of surgical anesthesia. Finally, Hollender takes the reader on an exotic tour, liberally sprinkled with case vignettes, of the role of memory in the dissociative disorders. Psychogenic amnesia, fugue, and multiple personality are familiar to everyone, as are the broad outlines of the concept of dissociation. However, Hollender does not stop there. Instead, he goes on to introduce the reader to a cluster of even more exotic disorders—pathological intoxication and, especially, the "culture-bound" syndromes (latah, amok, wihtigo, piblokto, and neginegi) in which amnesia appears to shield the person from blame rather than stress—and to argue that histrionic (formerly hysterical) personality, although not truly dissociative in nature, also involves a subtle memory disorder.

Like a good caterer, the editor has served up plenty for the main courses—but the desserts are just as substantial and satisfying. The book finishes off with a pair of clinically oriented papers. One, by Frankel, shows how hypnotic hypermnesia and age regression, for all their unreliability in the forensic situation, can be put to good use in psychotherapy. Kolb reviews the use of both hypnosis and barbiturate-induced "narcosynthesis" in the treatment of posttraumatic stress disorder in Vietnam veterans.

Finally, Pettinati herself tops off the volume with a very nice summary and look to the future. More than just the usual vague plea for more research, she gives a clear sense of what the salient clinical and experimental issues are: more field research to support field applications; more clinical research, especially systematic case series if not controlled studies; more attention to the assets and liabilities of nonhypnotic means of enhancing memory; and more attention to individual differences.

With all that is in this volume, one is reluctant to ask whether anything might be missing. In fact, there are a couple of things. There is relatively little attention paid to the social-psychological point of view of hypnosis—a view that offers quite a different perspective on the effects of hypnosis on memory. There is not much on the effects of hypnosis on the learning process—that is, on encoding as opposed to retrieval. And there is not anything concerning hypnotic effects on semantic as opposed to episodic memory. Having said that, it must be emphasized that the volume is quite full enough as it is. It is the kind of book the reader will wish he or she had edited, and one that everyone interested in memory will profit from reading.

Helen M. Pettinati, director of research at the Carrier Foundation (Belle Mead, New Jersey), is author of the chapter "Hypnosis, Hypnotizability, and the Bulimic Patient" in E. K. Baker and L. M. Hornyak (Eds.) Experiential Therapies for Eating Disorders.

John F. Kihlstrom, professor of psychology at the University of Arizona (Tucson), is the recipient of the American Psychological Association's Distinguished Scientific Award for an Early Career Contribution to Psychology. Kihlstrom is coauthor, with N. Cantor, of Personality and Social Intelligence.

Previously published in Contemporary Psychology: A Journal of Reviews, November 1989, Vol. 34, No. 11, 985–986
© 1989, American Psychological Association